Omega Centauri with the new Canon EOS Ra

[tornado33]

Hi all.
I finally upgraded from the old 350D when I heard of Canon's latest Astro camera. Lots of good reviews and a good discount at George's Cameras so I pulled the trigger. What a great camera. The 30x live viewmakes focusing super easy and the live view so sensitive there's plenty of stars visible and even the core of Omega Centauri. And yes the camera is sensitive to Hydrogen Alpha as it was designed to be yet amazingly takes great daytime images. Will post more pics soon.

Full 30 megapixel size here
https://www.astrobin.com/full/cvsfb8/0/?nc=all

Chuffed I can hand guide to that quality :)

[graham.hobart]

that is a lovely shot ! interesting camera too

[Geoff45]

Nice shot. Good colour. That old 350D was a great camera (I still have mine), but eventually the time comes to move on.

[multiweb]

:eyepop: Nicely resolved in the core with great colors. :thumbsup:

[Placidus]

Pro: Exceedingly good resolution. Nicely processed for dynamic range, colour and contrast. You've avoided the trap of making it look blue when it is really orange.

Con: You've got some serious tracking/guiding issues. Each star looks like a little Saturn. We've been having similar problems, now largely fixed, and we believe it was due to static friction in the mount bearings. Intentionally putting it out of balance so it wants to move freely to the east when you release the clutches helps hugely. For north-south, you need to know which way the guiding wants to go on average. If the polar axis alignment is such that you have to guide mostly north, balance it so it wants to move south when you release the clutches, and tell the guiding to only ever guide north. Vice versa of course in the opposite case. Because stiction is intermittent and unpredictable, you may find that most frames are pretty good but just a few are bad and should be tossed. Hope that helps.

[DavidU]

It was hand guided.

[Peter Ward]

The EOSRa is indeed a tidy camera...I have one kicking about here somewhere...but maaaate...get an autoguider next ;)

[tornado33]

It was an extremely wet night after rain earlier everything was dewing up so I had the electric blanket dew heater on high which seems to cause an air current elongating bright stars as shots I've taken on other nights don't show that. Eventually dew got onto the off axis guider pickoff prisms. Will upload some more pics soon

[Ryderscope]

Yep, definitely looks like a winner with the EOS Ra.

[tornado33]

Good advice re balancing the mount I do have it deliberately slightly out of balance to the east but not for the RA needle roller bearings which are super smooth rather the plastic worm wheel. I use Sharpcap for its incredibly accurate polar alingment, I can get within arc secs and get it done before its fully dark. Wind is a big issue as the scope with the big dewshield is a sail. But if I have the dew heat up too much it does affect the bright stars but the night was so wet water was running down the outside of the tube but the heat kept dew off the secondary

[Placidus]

Ah. Wind would do it.

[gregbradley]

I think you'll need to be careful with the white balance of your Ra. Its too red.

Ha modded cameras will be too red in general. I know Canon installs a custom white balance but its also easy enough to make your own with an 18% grey card at midday shot and set as the custom white balance.

Also when processing check the reds aren't exaggerated.

Greg.

[Peter Ward]

Indeed. Greg is correct.

None other than David Malin points out the the integrated colour of Omega Cent is in fact slightly blue.

An easy way to check is to apply a heavy Gaussian blur over the entire image.

Your rendition is "warm white"

It should look blue-white.

[tornado33]

Hows this, though the sky now seems slightly bluish, I always assumed globulars were populated with older yellowish stars and blue stragglers

[gregbradley]

Can you get the background sky to be more charcoal? It might require something like dynamic background extraction in PixInsight or some gradient removal technique in Photoshop (apply image tool).

Greg.